/*
 * Copyright 2016 The BigDL Authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.intel.analytics.bigdl.example.imageclassification

import com.intel.analytics.bigdl.dataset.{ByteRecord, Transformer}
import org.apache.log4j.Logger
import org.apache.spark.sql.Row

import scala.collection.Iterator

object RowToByteRecords {
  val logger = Logger.getLogger(getClass)

  def apply(colName: String = "data"): RowToByteRecords = {
    new RowToByteRecords(colName)
  }
}

/**
 * transform [[Row]] to [[ByteRecord]]
 * @param colName column name
 */
class RowToByteRecords(colName: String)
  extends Transformer[Row, ByteRecord] {

  override def apply(prev: Iterator[Row]): Iterator[ByteRecord] = {
    prev.map(
      img => {
        ByteRecord(img.getAs[Array[Byte]](colName), -1.0f)
      }
    )
  }
}
